Many cultures believe such things. Check Hawaiian beliefs on Aumakua.
As for me, I have experienced it twice in my life. I won't bore you with the details of the first, but the second time was on July 18th, 2012 around 2:30AM. My wife and I were sleeping when I heard my Mom's voice say "Gary, Honey, wake up." Thinking it was a pleasant dream, and in no way was her voice scary, I went back to sleep until I heard the voice again. I lifted my head, turned it towards our bathroom door, and there she was. She was not the mother I had just seen in the hospital a few weeks earlier, she was my Mom, standing straight and smiling. She gave me that tender look she always had and said, "Gary, it's okay, don't be afraid". Still clearing my eyes, and thinking I'd eaten too much pizza the night before, I closed them and opened them again and she was still there. "I love you." She said and was gone. Let me say that I am a firm believer in God, and Jesus Christ. I believe God, to comfort us both, allowed us to see each other again. The phone call at 6:00 AM was no surprise, nor was I surprised when I was told she'd died that night. What did surprise me was her time of death, 2:34 AM.
Be clear, we are not to seek out the dead:
· Leviticus 20:6, 27: Leviticus points out that God turns his back upon any person who , “prostitutes himself” (cf v 5) by pursuing communication with , “ghosts”, and , “departed spirits” (Lv 19:31).
Just remember the bible also says: "With God, All Things Are Possible." MATT 19:26 and MARK 10:27. While clearly, we do not worship the dead, (however according to records my Mom was not dead when she visited me), I do think that God surpasses our understanding and His Word says: “For my thoughts are not your thoughts, neither are your ways my ways,” declares the Lord. “As the heavens are higher than the earth, so are my ways higher than your ways and my thoughts than your thoughts." IS 55:8-9.
FINS UP! Land Shark